Selection of our books indexed in the Book Citation Index in Web of Science™ Core Collection (BKCI). Until 2001 she was a researcher in the Acoustics and Vibrations department of C.I.R.A. Italian Space Research Centre).
Introduction
Worldwide, 16% of hearing loss in adults is attributed to occupational noise.” Noise-induced hearing loss (NIHL) is a sensorineural hearing loss, explained by permanent threshold shift of hearing sensitivity. Investigations have shown that continuous noise exposure has an enormously harmful impact, not only on hearing, but also on the general health status of the population.
Literature review 1 Basics of acoustics
Overview of hearing loss
Conductive hearing loss is caused by damage to the external structures of the auditory system. It can be used to detect the specific severity of sensorineural hearing loss or to screen.
Consequences of NIHL
If the exposure to the harmful noise continues, the cellular integrity of the hair cells of the organ of Corti is gradually disrupted and eventually the nerve fibers innervating the hair cells will disappear, thus resulting in permanent threshold shift (PTS), and henceforth irreversible hearing loss will be noticed at higher frequencies. Hearing loss is detectable by performing an audiogram and is represented as a graph showing the weakest sounds a person can hear at different frequencies.
Methods and materials 1 Study design
Description of data collection Materials of use
Measuring device placed in the middle of the cabin at the level of the employees' ears. The sirens are located bilaterally on the roof and front spoiler of the ambulance car.
Research results
Sound level meter measurements
The first part involves collecting basic personal and work information through a 14-question questionnaire. For a good comparison of the ambulance service in Germany and Latvia, we have chosen comparable cars in model and age.
Questionnaire
One hundred and five Latvian and one hundred and two German emergency workers answered the questionnaire. The emergency workers in Germany are therefore older compared to the Latvian emergency workers (see Figure 3).
Discussion
Preventive measures Personal
Positioning of sirens as far as possible from the personnel, for example in front of the spoiler.
Conclusion
For both countries, the noise level is remarkably elevated during signal trips compared to non-signal trips. During emergency trips with signal use, the noise level is reaching and partially exceeding the safety limits of 80–85 dB(A).
Noise pollution becomes a main problem
However, knowledge about the direct and indirect effects of noise pollution on health is still insufficient. The lack of sufficient knowledge about the direct and indirect effects of these noises on health is limiting the provision of reasonable regulatory standards for residential noise.
Neighborhood noise is increasing
According to the International Program on Chemical Safety [2], the harmful effect of noise is defined as a change in the morphology and physiology of an organism that results in a deterioration of functional ability or a reduced ability to compensate for additional stress or increases the organism's susceptibility to the harmful effects of other environmental influences. The health effects of noise depend on its complexity, such as temporal variation, frequency content, loudness, ambient noise level, type of noise, and individual differences.
Neighborhood noise problem and the related efforts in Korea According to mediation center report, of the 137,813 telephone consultations
Most of the harms reported to the Mediation Center were sleep disturbance, followed by rest disturbance, excessive protest of the victim, emotional distress and learning disability. The intention of the law is to preserve proper environment, which requires the establishment of various measures, such as essay.
Environmental noise indicators of the health impacts
Accept: Implementation of second step service Reject: Noise reduction, conflict mitigation measures Mail notification (end). In Korea, a law has been passed regarding intermediate noise that is stricter than that of other countries, considering heavy impact, light impact noise and the maximum time-weighted noise level (Lmax).
Health outcomes of the noise exposure
Disability severity is a weighting factor that reflects the severity of the disease on a scale from 0 (perfect health) to 1 (equivalent to death). Lnoč) • Percentage of the population with severe sleep disturbances (%HSD), according to self-assessment, assessed with a standardized scale.
The burden of environmental noise and adverse health outcome The disability weight (DW) is used to rank the priority critical health outcome
Environmental noise burden and adverse health outcome Disability weighting (DW) is used to rank priority critical health outcome Disability weighting (DW) is used to rank priority measures of critical health outcomes. Important health outcomes and health outcome measures revised according to the WHO Environmental Noise Guidelines for the European Region.
Mental health impacts of noise
There was no prioritization of health outcome measures leading to rationale for selection, as important health outcomes had less impact on the development of recommendations. In Table 7, the health outcome-related noise indicator was Lden, and the most common health outcomes were relevant to psychoacoustic issues such as quality of life, well-being and mental health [20].
Conclusion
WHO environmental noise guidelines for the European region: A systematic review on environmental noise and cognition. WHO Environmental Noise Guidelines for the European Region: A Systematic Review on Environmental Noise and Nuisance.
Design of the proposed algorithm and scheme
The proposed technique adapts to the conditions of the environment where it is implemented. The condition that the signal must remain representative of the original must be taken into account.
Results of the implementation
Minimizing the mean square value of the error signal means maximizing the signal-to-noise ratio of the system output. The designed filter adapts to the conditions of the environment in which it is implemented.
Conclusion
We can see that combining the previous two frequency responses produces a frequency domain response through the filter. On the other hand, we also thank the Instituto Politécnico Nacional, which provided us with its facilities for experimentation and real tests of the system I proposed.
A traditional approach: noise barriers
Noise barrier types
These are ground noise barriers, construction noise barriers and a combination of the first two types. Sound barriers can be defined as some sound "obstacle" between the sound source and the observer, i.e.
Material features
Such materials can be used as noise barriers' filling and with their sound absorption properties increase the noise barrier efficiency. Typical values of the noise barriers transmission loss (TL) parameter when looking at the A-weighted characteristic are from 10 dBA to 15 dBA.
A contemporary approach: soundscape
- Soundscape definition
- Soundscape classification
- How to record a soundscape?
- Soundscape analysis
- Using the soundscape as a noise reduction instrument
Taking all of the above into account, we can conclude that the concept of soundscape as a research field is extremely broad and requires a multidisciplinary approach. The recording takes place at the height of the walker (binaural microphones are placed in the walker's ears) and therefore the recorded signals are similar (at the highest possible level) to the signals heard by pedestrians in this environment (Figure 11).
Combining the traditional and contemporary approach
Finally, noise barriers as a solution are focused only on reducing noise levels from traffic sources, while the common and ultimate goal of WHO and researchers with different types of expertise is to improve the overall quality of life by using different tools, guidelines, descriptors and an interdisciplinary approach by designing, maintaining and researching pleasant acoustic environments, i.e. ed on the reduction of noise levels from traffic sources, while the WHO and many researchers aim to improve the overall quality of life using various tools, guidelines, descriptors and an interdisciplinary approach by planning, preserving and researching positively perceived soundscapes, as already mentioned.
Conclusions
Genetic algorithm optimization of the acoustic performance of T-shaped noise barriers with a reactive top surface. Research shows that traffic noise in urban areas has increased tremendously since the turn of the century, largely due to increased transportation of people and goods.
Traffic noise sources 1 Road traffic noise
Railway traffic noise
On the propulsion system, noise is mainly generated by the operation of the traction engine (suction and exhaust process in the case of the diesel engine, which is also the noisiest type of engine), the engine cooling system, the transmission system and the ventilation system. The noise generated by the braking process, in addition to the roughness of the wheels and the contact surfaces of the track, depends significantly on the type and shape of brakes used.
Aircraft traffic noise
When moving on straight railway sections, noise is created mainly as a result of the roughness of the surfaces of the wheel and the rail, i.e. due to their friction. The noise produced by the flaps is generated by the outer edges of the flaps.
Other types of noise sources
The worst consequence of long-term exposure to this type of noise is permanent hearing impairment. Considering the noise generated by the various construction sites shown in Figure 9, this type of noise can have extremely high noise levels.
Ten ways how to reduce noise levels
- Electric vehicles
- Smart traffic management
- Changing driving styles
- Quiet road surfaces
The approved amendment states that "the sound generated by the AVAS must be a continuous sound of the vehicle during operation, providing information to pedestrians and vulnerable road users." Tires selected for severe weather conditions will make more noise due to certain safety considerations, ie. the need for better grip on the road.
Conclusions
Physical model description
Schematic of the airflow window system with photovoltaic solar wall section (dimensions given are in mm). One option is to treat the heated PV module as an absorber surface and allow air flow through the surface.
State-of-the-art
- Absorption of sound
- Noise and its effects
- Integrated sound and thermal insulation
- Thermal insulation definition
The absorbing capacity of the absorbent materials depends on the thickness of the material, its density and sound frequency. General principles: The following are the general principles of thermal insulation:. i) the thermal resistance of an insulating material is directly proportional to its thickness. ii) Provision of an air gap is a very important means of insulation and is very important. iii).
Model assumptions and development
Noise characterization
The packet of solar energy waves and thermal energy waves (for the same intensity I), have the same energy areas, therefore their noise units are the same as Sol. Packets of solar energy waves and electric energy waves (for the same intensity I), have the same energy areas, therefore their noise units are the same as Sol.
Noise reduction coefficients
The reference value of I2 is −1 W m−2 with I1 on the positive noise scale, should be taken with the negative noise measurement expression (see equations 3, 5 and 7) and therefore gives positive noise values;. The reference value of I2 is 1 W m−2 with I1 on the negative noise scale, must be taken with the positive noise measurement term (see equations 3, 5 and 7) and therefore gives negative noise values.
Model assumptions and development
Some examples of sound insulation calculations are illustrated using newly developed sound measurement equations for noise from sol, noise from therm, noise from scatter. The thermophysical properties of photovoltaic modules, air and insulation panels were assumed to be constant in all directions, i.e. The thermophysical properties of insulation panels with building insulation were obtained from tests performed with a heat flow meter and related manufacturer's specifications [3].
Conclusion
Oral presented at the Proceedings of the Second International Conference on Green Energy; 25-29 June 2006; Oshawa, Canada. In: Accepted Abstract in the Proceedings of The 3rd International Energy, Exergy and Environment Symposium; July 1-5, 2007; Évora, Portugal.
Formulation of the problem
The thickness of the considered multilayer structure and the ith layer are denoted by h and hi, respectively. We have also considered in the present study thatτab,b¼μi0ϵabfJbHf is the a-component of the Lorentz force and Jð Þ ¼τ Jτ02τ.
Continuity and initial and boundary conditions
Tiαis the temperature; Ciabfgandβiabare, respectively, the constant elastic moduli and stress-temperature coefficients of the anisotropic medium;μi,~h, Pi,ρi, and ciαare the magnetic permeability, disturbed magnetic field, initial stress in the ith layer, density and specific heat capacity, respectively;, and0,τ is the time relaxation; i¼1, 2,. We also considered in the present study thatτab,b ¼μi0ϵabfJbHf is the a-component of the Lorentz force and Jð Þ ¼τ Jτ02τ.
BEM numerical implementation
Using integration by division and property of the Dirac distribution seven for (26), then Eq. 27) and (29), we can write the following formula for the representation of elastic integral: . uida∗tia�tida∗uia�uida∗βiabTiαnb. Now the coefficients α can be expressed in terms of node values of the unknown displacements Ui, velocitiesU_i and accelerationsU€ia as follows:.
Numerical results and discussion
The DRBEM solution of the generalized magneto-thermo-viscoelastic problems in 3D anisotropic functionally graded solids. Computer implementation of the DRBEM for a new BEM for modeling acoustic wave propagation in three-temperature nonlinearity.
Ambient noise: frequency dependency
Ambient noise due to intermittent sources
- Marine life
- Natural physical processes
- Human activities
- Rain noise
- Shipping noise
- Wind-generated noise
Ambient noise in the frequency range of 500 Hz to 50 KHz was found to be a function of wind speed. Wind speed is considered a major component of environmental noise in the absence of ships and turbulent marine life.
Ambient noise level
Wind noise in the frequency range from 500 Hz to 20 KHz is called Knudsen noise, because Knudsen discovered that it correlates very well with wind speed [7].
Ambient noise in shallow water
Shallow water environmental noise is highly random due to the waveguide nature of the environment and reflection from the bottom [12]. Ambient noise is greater in shallow water because the noise is trapped between the seabed and the ocean surface.
Characterization and denoising of ambient noise
In shallow water (depth of 5–200 m), acoustic systems such as sonar, sonar and sub-bottom profilers suffer a large loss due to ambient noise [13]. Therefore, to improve the efficiency of underwater acoustic instruments, the measurement and characterization of ambient noise is more significant.
Conclusion
The recovery of signal buried in ambient noise is important for low signal-to-noise ratio target signal detection, recognition and classification (Tieshuang et al. [14]). In this chapter we have made a detailed study about the noise of the underwater environment, the different sources that produce the noise and the noise of the shallow water environment.
